Chondroblastoma of foot bones; a clinicopathological study of 29 cases confirming the diagnostic utility of H3K36M and H3G34W antibodies at an uncommon site.

OBJECTIVE: Chondroblastoma (CB) is a benign cartilaginous bone neoplasm which commonly occurs in long bones of adolescents. CB can uncommonly involve foot. Its mimics include both benign and malignant lesions. H3K36M immunohistochemical (IHC) stain is a helpful tool for establishing the diagnosis of CB in such challenging situations. In addition, H3G34W IHC stain helps to rule out giant cell tumor which is the closest differential of CB. Our objective was to describe the clinicopathological features and frequencies of H3K36M, H3G34W and SATB2 IHC stains in CB of foot. MATERIALS AND METHODS: We reviewed H&E slides and blocks of 29 cases diagnosed as "chondroblastoma" of foot at our institutions. RESULTS: Patient's age ranged from 6 to 69 (mean: 23.3 and median: 23) years. Males were almost 5 times more commonly affected than females. Talus and calcaneum were involved in 13 (44.8 %) cases each. Microscopically, tumors were composed of polygonal mononuclear cells and multinucleated giant cells and chondroid matrix. Other histological features included aneurysmal bone cyst-like (ABC-like) change (44.8 %), osteoid matrix (31 %), chicken-wire calcification (20.7 %), and necrosis (10.3 %). H3K36M was expressed in 100 % and SATB2 in 91.7 % cases. H3G34W was negative in all cases, where performed. One out of 11 patients with follow up information developed local recurrence after 48 months. CONCLUSION: CB in foot occur at an elder age and show more frequent ABC-like changes as compared to long bones. Males are affected ~5:1 as compared to 2:1 in long bones. H3K36M are H3G34W are extremely useful diagnostic markers for CB, especially elderly (aged or higher) patients and we report the largest series of foot CB cases confirmed by immunohistochemistry.

Morphometric examination of hind limb and foot bones and fibre type composition of crus region muscles in quail and pigeon.

In this study, the foot and hind limb bones of pigeons and quails were measured morphometrically. Additionally, microscopic classifications of the muscles affecting the foot and digit joints were made. For the macroscopic inspection, 40 birds were used, including 20 adult quails (10 males, 10 females) and 20 adult pigeons (10 males, 10 females). Diethyl ether was inhaled to anaesthetize the animals. The poultry animals were put under anaesthesia, and radiographic pictures of their left feet were obtained individually. DAP measurements were performed separately from the images taken with the Image J program. Then, they were euthanized by cervical dislocation under diethyl ether anaesthesia. The right legs of the euthanized animals were preserved in a 10% neutral formalin solution for histology procedures just after the legs were dissected from the trunk. Morphometric measurements of bone lengths were made in accordance with the measurement points specified by von den Driesch. After fixation for histological examination, routine tissue follow-up was performed and the tissues were embedded in paraffin. The presence of SO-type I, FG-type IIb and FOG-type IIa in 4-5 µ sections taken from paraffin blocks was demonstrated using the indirect streptavidin-biotin-complex method from immunohistochemical methods. The result of our study was statistically evaluated at p < 0.05 and p < 0.001 levels. The length of the hallux, the articulation point to the TMT and the fibre arrangements in the two flexor group muscles showed that the hind limbs and feet of the pigeons had a more favourable anatomical and histological structure for the perching movement.

Estimación de la osificación de los huesos del pie sobre población extremeña. Estudio observacional / Estimation of the ossification of the bones of the foot about the population of Extremadura. Observational study

Objetivos: La estimación de la edad de un individuo es un tema de interés dentro del ámbito de la Medicina Legal y Forense. Una de las herramientas más utilizadas para este fin es la Radiología. Los objetivos son la cuantificación de las edades de osificación de cada hueso del pie y determinar si existe relación entre la osificación de los huesos y el sexo del individuo. Pacientes y métodos: La población de estudio se compuso de 2476 radiografías digitales, pertenecientes a un total de 816 sujetos en periodo de crecimiento. El análisis de las imágenes se realizó mediante la aplicación del método validado y diseñado para la estimación de la edad en meses sobre la radiografía del esqueleto del pie.Resultados: Sí existe diferencia en la osificación ósea de la población extremeña frente a la literatura (p valor < 0.05). Todos los huesos que forman el Tarso poseen significación estadística en la comparación por sexos a excepción del cuboides, el cuneiforme medial y el cuneiforme lateral. Conclusiones: Sí existe diferencia significativa en la osificación de hueso del pie entre sexos y entre poblaciones de diferente raza.(AU)

Objectives: The estimation of the age of an individual is a topic of interest within the field of Legal and Forensic Medicine. One of the most used tools for this purpose is Radiology. The objectives of the present work are the quantification of the ages of ossification of each bone of the foot and to determine if there is a relationship between the ossification of the bones and the sex of the individual.Patients and methods: The study population was made up of 2476 digital radiographs, belonging to a total of 816 subjects in the growth period. The analysis of the images was carried out by applying the method validated and designed for the estimation of age in months on the X-ray of the skeleton of the foot. Results: If there is a difference in the bone ossification of the population of Extremadura compared to the literature (p value < 0,05). All the bones that form the tarsus have statistical significance in the comparison by sex, except for the Cuboid, the Medial Cuneiform and the Lateral Cuneiform. Conclusions: If there is a significant difference in foot bone ossification between sexes and between populations of different races.(AU)

Influencia del tratamiento quirúrgico para el hallux abductus valgus en la movilidad del primer radio / Influence of surgical treatment of hallux abducto-valgus on first ray mobility

Objetivo: El objetivo principal de este trabajo es determinar la variación de movilidad pre y postquirúrgica del primer radio. Pacientes y métodos: El diseño corresponde a un estudio prospectivo de series de casos en pacientes sometidos a cirugía de hallux valgus. Se valoró en 13 pies la movilidad del primer radio con el medidor del primer radio, la flexo-extensión de la primera articulación metatarsofalángica, el ángulo de Clarke y el “Arch Index” en pedigrafías, los ángulos hallux valgus e intermetatarsal I-II en radiografías dorsoplantares en carga, y la postura general del pie mediante el “Foot Posture Index” antes y después de ser sometidos a cirugía de hallux valgus. Todo ello con un periodo de seguimiento de 6 meses. Resultados: El rango total de movilidad del primer radio pasó de 11.74 ± 1.88 mm a 6.72 ± 2.20 mm; y el de la primera articulación metatarsofalángica pasó de 79.62° ± 22.33° a 48.69° ± 18.69° tras la cirugía. Los ángulos radiográficos de hallux valgus y ángulo intermetatarsal disminuyeron una media de 19.07° ± 8.20° y 7.23° ± 2.97°, respectivamente. El ángulo de Clarke cambió de 41.31° ± 10.79° a 38.31° ± 11.00°. El “Arch Index” cambió de 0.24 ± 0.06 a 0.25 ± 0.05. Y el “Foot Posture Index” pasó de 6.70 ± 3.33 de media antes de la cirugía a 5.46 ± 3.86 tras la misma. Conclusión: En los participantes incluidos en este estudio se observó una disminución generalizada de todas las variables examinadas tras la cirugía, a excepción de los parámetros valorados en las pedigrafías, que no llegaron a presentar diferencias relevantes.(AU)

Objectives: The main aim of this work is to determine the variation of first ray mobility before and after surgery. Patients and methods: The design corresponds to a prospective case series of patients operated of hallux valgus. A total of 13 feet have been included in this study. Measurements of the first ray mobility were obtained using the first ray mobility measurer. Furthermore, we assess the flexo-extension of the first metatarsophalangeal joint. The Clarke’s angle and the Arch Index were evalued on weightbearing footprints. The hallux valgus angle and intermetatarsal I-II angle were made on weightbearing dorsal-plantar projection radiographs. And finally, the general posture of the foot was quantified using the Foot Posture Index. All this with pre and post measurements of hallux valgus surgery and with a follow-up period of 6 months. Results: The total range of motion of the first ray decreased from 11.74 ± 1.88 mm to 6.72 ± 2.20 mm; and the range of motion of the first metatarsophalangeal joint underwent from 79.62° ± 22.33° to 48.69° ± 18.69° after surgery. The hallux valgus angle and intermetatarsal I-II angle decreased by a mean of 19.07° ± 8.20° and 7.23° ± 2.97°, respectively. The Clarke’s angle changed from 41.31° ± 10.79° to 38.31° ± 11.00°. The Arch Index changed from 0.24 ± 0.06 to 0.25 ± 0.05. And the Foot Posture Index went from 6.70 ± 3.33 before surgery to 5.46 ± 3.86 after it. Conclusion: In the participants included in this study, a generalized decrease was observed in all the examined variables after surgery, except for the parameters assessed in the pedigraphs, which did not present relevant differences.(AU)

Extraction and Analysis of Foot Bone Shape Features Based on Deep Learning.

With the rapid development of artificial intelligence, more and more researchers and research institutions begin to pay attention to the bone feature recognition field. Human bone movement is very complex, and human bone shape recognition technology can be widely used in medical treatment, sports, and other fields. At present, there are mainly two kinds of methods for extracting the shape features of human foot bone based on optical image acquisition technology and sensor information perception technology. However, due to the interference factors such as target posture change, camera shake, and individual behavior differences, it is still a very challenging task to design a robust algorithm for extraction and analysis of foot bone shape features. In recent years, convolutional neural network- (CNN-) based foot contour feature recognition methods emerge one after another and have made breakthrough progress. How to use and how to fully explore the potential relationship of various characteristics contained in the foot bone data and how to enhance the robustness of view changes and other aspects need to be further studied. In this context, this paper proposed an improved CNN model, which not only has the capability of deep feature extraction of the CNN model but also can obtain the optimal model parameters with the combination of particle swarm optimization algorithm. The effectiveness of the proposed method in the extraction and analysis of foot bone shape features is verified in the simulation experiment.

Divergent locomotor evolution in "giant" kangaroos: Evidence from foot bone bending resistances and microanatomy.

The extinct sthenurine (giant, short-faced) kangaroos have been proposed to have a different type of locomotor behavior to extant (macropodine) kangaroos, based both on physical limitations (the size of many exceeds the proposed limit for hopping) and anatomical features (features of the hind limb anatomy suggestive of weight-bearing on one leg at a time). Here, we use micro computerised tomography (micro-CT) scans of the pedal bones of six kangaroos, three sthenurine, and three macropodine, ranging from ~50 to 150 kg, to investigate possible differences in bone resistances to bending and cortical bone distribution that might relate to differences in locomotion. Using second moment of area analysis, we show differences in resistance to bending between the two subfamilies. Distribution of cortical bone shows that sthenurines had less resistant calcaneal tubers, implying a different foot posture during locomotion, and the long foot bones were more resistant to the medial bending stresses. These differences were the most pronounced between Pleistocene monodactyl sthenurines (Sthenurus stirlingi and Procoptodon browneorum) and the two species of Macropus (the extant M. giganteus and the extinct M. cf. M. titan) and support the hypothesis that these derived sthenurines employed bipedal striding. The Miocene sthenurine Hadronomas retains some more macropodine-like features of bone resistance to bending, perhaps reflecting its retention of the fifth pedal digit. The Pleistocene macropodine Protemnodon has a number of unique features, possibly indicative of a type of locomotion unlike the other kangaroos.

Body proportions and environmental adaptation in gorillas.

OBJECTIVES: Limb length and trunk proportions are determined in a large, taxonomically and environmentally diverse sample of gorillas and related to variation in locomotion, climate, altitude, and diet. MATERIALS AND METHODS: The sample includes 299 gorilla skeletons, 115 of which are infants and juveniles, distributed between western lowland (G. gorilla gorilla), low and high elevation grauer (G. beringei graueri), and Virunga mountain gorillas (G. b. beringei). Limb bone and vertebral column lengths scaled to body mass are compared between subgroups by age group. RESULTS: All G. beringei have relatively short 3rd metapodials and manual proximal phalanges compared to G. gorilla, and this difference is apparent in infancy. All G. beringei also have shortened total limb lengths relative to either body mass or vertebral column length, although patterns of variation in individual skeletal elements are more complex, and infants do not display the same patterns as adults. Mountain gorillas have relatively long clavicles, present in infancy, and a relatively long thoracic (but not lumbosacral) vertebral column. DISCUSSION: A variety of environmental factors likely contributed to observed patterns of morphological variation among extant gorillas. We interpret the short hand and foot bones of all G. beringei as genetic adaptations to greater terrestriality in the last common ancestor of G. beringei; variation in other limb lengths to climatic adaptation, both genetic and developmental; and the larger thorax of G. b. beringei to adaptation to reduced oxygen pressure at high altitudes, again as a product of both genetic differences and environmental influences during development.

Trombose da artéria dorsal do pé como complicação de os intermetatarseum sintomático: relato de caso raro / Thrombosis of the dorsalis pedis artery as a complication of symptomatic os intermetatarseum: a rare case report

Introdução: O os intermetatarseum é um ossículo acessório do pé observado mais frequentemente entre o cuneiforme medial e a base do primeiro e segundo metatarsal. Desde sua descrição, há raros relatos na literatura de casos sintomáticos e até o momento de produção desse relato não foi descrito a relação com a trombose da artéria dorsal do pé. Relato de caso: Paciente do sexo masculino, 24 anos, atleta não profissional, relata dor súbita no dorso do mediopé associado a atividade esportiva, sem melhora ao tratamento conservador, sendo submetido a ressecção do osso acessório e do trombo da artéria pediosa, evoluindo com melhora dos sintomas iniciais. Discussão: O os intermetatarseum é um dos mais raros dos ossos acessórios que podem ser encontrados no pé e geralmente é assintomático, sendo correlacionado como causa de hálux valgo secundário. Porém, é um importante diagnóstico diferencial a ser lembrado em quadros dolorosos no dorso do mediopé e em caso de sintomas compressivos do nervo fibular profundo. Conclusão: O os intermetatarseum é tipicamente assintomático, porém deve ser lembrado em quadros álgicos do dorso do pé e sintomas compressivos do nervo fibular profundo, especialmente em jovens praticantes de atividades esportivas. Palavras-chave: Intermetatarseum. Ortopedia. Pé. Artéria dorsal do pé.

Management of Chronic Osteomyelitis by an Orthoplastic Team: 7-Year Experience of a University Hospital.

BACKGROUND: Treating chronic osteomyelitis of the lower extremities is challenging. The treatment of acute lower limb trauma by orthoplastic teams has shown good results over the past few decades. This study aimed to characterize surgical outcomes of leg and heel chronic osteomyelitis by an orthoplastic team. METHODS: The cases of 113 consecutive leg and heel chronic osteomyelitis patients undergoing soft-tissue reconstruction with an orthopedic procedure were reviewed in this retrospective single-center observational study. The main objective was to assess surgical outcomes of skin healing and gait recovery at the 1-year follow-up. The secondary objective was to evaluate the global success rate at the last follow-up. RESULTS: The median follow-up was 19.7 months. A free flap was performed for 33 patients (29.2 percent) and a locoregional flap was used in 79 patients (69.9 percent). Seventy-two patients (63.7 percent) had chronic osteomyelitis on continuous bone. The others had a septic pseudarthrosis with a mean bone defect length of 42.9 mm. Forty-four patients (38.9 percent) underwent curettage only, eight (7.1 percent) underwent curettage and cement, 20 (17.7 percent) underwent curettage and bone fixation, and 39 (34.5 percent) underwent the Masquelet technique. At the 1-year follow-up, 72 patients (63.7 percent) had achieved skin healing and had recovered their gait. The success rate at all follow-up time points was 82.3 percent. The median time to achieve skin healing was 6.5 months and that to bone union in cases of septic pseudarthrosis was 7.9 months. CONCLUSION: Orthoplastic management of leg and heel chronic osteomyelitis patients with combined soft-tissue reconstruction using an orthopedic procedure was a viable strategy that offered good results even though the time to complete healing was long. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.

Pes Cavus Deformity: Anatomic, Functional Considerations, and Surgical Implications.

Pes cavus is a complicated, multiplanar deformity that requires a thorough understanding in order to provide the appropriate level of care. The foot and ankle surgeon should perform a comprehensive examination, including a neurologic evaluation, in the workup of this patient population. Understanding the cause of the patient's deformity is a critical step in predicting the disease course as well as the most acceptable form of treatment. The surgical correlation with the patient's pathologic anatomy requires an in-depth clinical evaluation, in addition to the radiographic findings, as the radiographic findings do not necessarily correlate with the patient's discomfort.

Clinical outcome of a conservative approach to giant cell tumor of ankle and foot bones.

Giant cell tumor of the bone (GCTB) affecting foot and ankle is rare, and the literature available on their clinical behavior and reconstructive options is scarce. Many authors consider these sites a special subset with high rates of local recurrence. Eighteen patients with GCTB of foot and ankle were treated from (March 2014 to February 2020). Extended curettage was offered wherever feasible. Twelve patients underwent extended curettage, three underwent resection and reconstruction, one patient had ray amputation, one had below knee amputation. One patient with multifocal disease was treated conservatively with denosumab. There were 11 females and the mean age was 31.7 years. Distal tibia (11 patients) was the commonest location, followed by the first metatarsal (four patients). At a median follow up of 46 months, two patients out of the 17 operated had a local recurrence. GCTB affecting the foot and ankle have a clinical course comparable to those at other locations. They should be treated with a conservative approach, where radical resection and amputation are reserved for only the non-curettable tumors.

[Unusual presentation of late reactivated tuberculosis in immunosenescence after nine decades latency]. / Ungewöhnliche Spätmanifestation einer reaktivierten Tuberkulose in der Immunseneszenz nach 9 Dekaden Latenz.

INTRODUCTION: Tuberculosis is an often underestimated infectious disease which can lead to manifest infections even after years of latency. Pulmonary manifestations are by far the most frequent, although any other organ can be equally affected. HISTORY: A 95-year old patient presented with a localized painful swelling of the right foot for further investigation. Despite her advanced age there were no pre-existing medical conditions, except for a club foot existing since early childhood. FINDINGS AND DIAGNOSIS: On physical examination we found a hyperemic fluctuant swelling of 5 cm diameter at the arch of the right foot. The X-ray showed a complete destruction of the regular osseous structures from the upper ankle joint to the proximal metatarsal bones. THERAPY AND COURSE: Intraoperatively the suspicion of an abscess was confirmed and material was obtained for microbiological investigation. Liquid cultures grew Mycobacterium tuberculosis. In an MRI-scan, involvement of the tarsal and metatarsal bones could not be excluded, thus the duration of the standard antituberculose treatment was set to 9 months. CONCLUSIONS: Tuberculosis, primary or reactivated, should always be considered as a potential cause of unclear infections; especially in patients with anticipated immunosenescence.

Ultrasonographic diagnosis of closed pedal bone fractures in bovine claws: An ex-vivo study in slaughterhouse specimens.

Pedal bone fractures are one of the most common fracture locations in adult cattle and can be diagnosed by radiographs in two planes. Most bovine practitioners do not have access to such X-ray machines, but many use ultrasound units on a daily basis, primarily for reproductive medicine. For this reason, in this double-masked, randomized controlled study, we aimed to investigate the suitability of ultrasonographic examination using a 5 MHz linear transducer for diagnosing closed fractures of the pedal bone in cattle. A total of 54 hindlimb claws from slaughtered cattle were prepared and approximately 50% of the claws were artificially fractured. All claws were ultrasonographically examined twice by two examiners to determine the presence or absence of fractures and their locations. Ultrasound results were confirmed using radiographs of the claws as the reference standard method. All fracture locations as determined by ultrasonography were situated within ±2 mm of the radiographically-determined fracture zone. Ultrasound examination yielded a calculated sensitivity of 93%, a specificity of 91% and an inter-rater reliability of 0.77. The intra-rater reliability for the examiners were 0.96 and 0.88. Examiner experience with ultrasound examination and using ultrasound images for diagnosis could have influenced diagnostic accuracy. We conclude that artificially-created pedal bone fractures in ex-vivo bovine claws can be diagnosed using ultrasonography; similar results are expected in live animals. These results should encourage veterinarians to use ultrasonography for diagnosing pedal bone fractures in cattle.

Early Upper Paleolithic human foot bones from Manot Cave, Israel.

The transition from the Middle Paleolithic to the Upper Paleolithic in the Levant represents a major event in human prehistory with regards to the dispersal of modern human populations. Unfortunately, the scarcity of human remains from this period has hampered our ability to study the anatomy of Upper Paleolithic populations. This study describes and examines pedal bones recovered from the Early Upper Paleolithic period at Manot Cave, Israel, from 2014 to 2017. The Manot Cave foot bones include a partial, left foot skeleton comprising a talus, a calcaneus, a cuboid, a first metatarsal, a second metatarsal, a fifth metatarsal, and a hallucal sesamoid. All these remains were found in the same archaeological unit of the cave and belong to a young adult. Shape and size comparisons with Neanderthals, Anatomically Modern Human and modern human foot bones indicate a modern human morphology. In some characteristics, however, the Manot Cave foot bones display a Neanderthal-like pattern. Notably, the Manot Cave foot is remarkable in its overall gracility. A healed traumatic injury in the second metatarsal (Lisfranc's fracture) is most likely due to a remote impact to the dorsum of the foot. This injury, its subsequent debility, and the individual's apparent recovery suggest that the members of the Manot Cave community had a supportive environment, one with mutual responsibilities among the members.

The Utility of SPECT/CT in Diagnosing Haglund Syndrome With Bone Scintigraphy.

Haglund syndrome-the combination of Haglund's deformity, retrocalcaneal bursitis, and achilles tendinopathy-is a common cause of hind foot pain in adults; however, diagnosis on planar scintigraphy can be challenging. We present a case of Haglund syndrome and show the key role that SPECT/CT can play in its diagnosis.

Outcomes after nonoperatively treated non-displaced Lisfranc injury: a retrospective case series of 55 patients.

BACKGROUND: Current knowledge of the role of the nonoperative treatment of Lisfranc injuries is based on a few retrospective case series. Hence, consensus on which patients can be treated nonoperatively does not exist. The aim of this study was to investigate outcomes after nonoperative treatment of Lisfranc injuries. METHODS: In this study, patients were collected by recruiting all computer tomography-confirmed Lisfranc injuries treated during a 5-year period at a major trauma hospital. Between 2 and 6 years after suffering the injury, patients completed the visual analogue scale foot and ankle questionnaire. RESULTS: In total, 55 patients returned adequately completed questionnaires and were included in the study. Of those, 22 patients had avulsion fractures and 33 had simple non-displaced intra-articular fractures. Of these patients, 30 (55%) scored over 90 points in both the pain and function subscales of the VAS-FA, and 35 (64%) scored over 90 points overall. In addition, three (5%) patients scored under 60 points in both the pain and function subscales of the VAS-FA, and four (7%) scored under 60 points overall. Only one patient with avulsion fractures underwent secondary surgery. CONCLUSION: Nonoperative treatment has a role in the treatment of Lisfranc injuries, and the results of our study support the view that avulsion and simple intra-articular fractures with < 2 mm of displacement can be treated nonoperatively with high functional outcomes. The results of nonoperative and operative treatment should be compared in a prospective randomized controlled study setting in future studies. LEVEL OF EVIDENCE: IV, retrospective case series.

Anatomical variations of the tibialis anterior tendon.

INTRODUCTION: The tibialis anterior muscle originates from the medial part of the anterior compartment, from the upper two-thirds of the lateral surface of the tibia and the adjacent part of the interosseous membrane, and typically inserts to the medial cuneiform and first metatarsal bone. The goal of the study was to examine the insertion of the tibialis anterior tendon and create a classification in human fetuses. MATERIALS AND METHODS: Fifty spontaneously-aborted human fetuses (26 male, 24 female, 100 lower limbs), aged 18-38 weeks of gestation at death were examined. RESULTS: The classification comprised five types of tibialis anterior tendon insertion. The most common was Type V (60%), which was characterized by a single tendon inserting onto the medial cuneiform bone. The second most frequent was Type I (19%), which was characterized by a tendon which split into two equal-sized parts that insert to the medial cuneiform bone and the base of the first metatarsal. The third was Type II (12%), which was characterized by a tendon splitting into two different-sized parts that inserted onto the medial cuneiform bone (larger component) and the base of the first metatarsal (smaller component). The fourth type was Type III (5%), which was also characterized by a tendon splitting into two different-sized parts that inserted onto the medial cuneiform bone (smaller component) and the base of the first metatarsal (larger component). Finally, Type VI (4%), the least frequent type, was characterized by a tendon splitting into three different-sized parts, inserting onto the medial cuneiform bone (the smallest component) and the base of the first metatarsal (the middle and larger component). CONCLUSION: The tibialis anterior muscle is characterized by high variability in the approach of its tendon to the foot, at least in fetuses. This is classified in the present study for the first time.

Techniques for 3D foot bone orientation angles in weight-bearing from cone-beam computed tomography.

BACKGROUND: For the diagnosis and treatment of foot and ankle disorders, objective quantification of the absolute and relative orientation angles is necessary. The present work aims at assessing novel techniques for 3D measures of foot bone angles from current Cone-Beam technology. METHODS: A normal foot was scanned via weight-bearing CT and 3D-model of each bone was obtained. Principal Component Analysis, landmark-based and mid-diaphyseal axes were exploited to obtain bone anatomical references. Absolute and relative angles between calcaneus and first metatarsal bone were calculated both in 3D and in a simulated sagittal projections. The effects of malpositioning were also investigated via rotations of the entire foot model. RESULTS: Large angle variations were found between the different definitions. For the 3D relative orientation, variations larger than 10 degrees were found. Foot malposition in axial rotation or in varus/valgus can result in errors larger than 5 and 3 degrees, respectively. CONCLUSIONS: New measures of foot bone orientation are possible in 3D and in weight-bearing, removing operator variability and the effects of foot positioning.

Structural Characteristics Associated With Radiographic Severity of First Metatarsophalangeal Joint Osteoarthritis.

OBJECTIVE: To determine whether foot structure varies according to the presence and radiographic severity of first metatarsophalangeal (MTP) joint osteoarthritis (OA). METHODS: Weight-bearing dorsiplantar and lateral radiographs were obtained for the symptomatic foot of 185 participants (105 women, ages 22-85 years) with clinically diagnosed first MTP joint OA. A validated atlas was used to classify participants as having radiographic first MTP joint OA and to stratify into 3 categories of severity (none/mild, moderate, severe). Bone length and width and angular measures of the forefoot and medial arch were performed on radiographs, and differences between categories were compared using univariate general linear models, adjusting for confounders. RESULTS: A total of 150 participants were categorized as having radiographic first MTP joint OA, and participants were further stratified into none/mild (n = 35), moderate (n = 69), or severe (n = 81) OA categories. Participants with radiographically defined first MTP joint OA displayed a greater hallux abductus interphalangeal angle. Greater radiographic severity of first MTP joint OA was associated with a larger hallux abductus interphalangeal angle, a wider first metatarsal and proximal phalanx, and a smaller intermetatarsal angle. No differences in medial arch measurements were observed between the categories. CONCLUSION: First ray alignment and morphology differed according to the presence and severity of first MTP joint OA. Prospective studies are required to determine whether the observed differences are a cause or consequence of OA.